A. FIELD OF THE INVENTION
The present invention relates to a plug-in electrical interconnect system and, in particular, to interconnect components used in the plug-in electrical interconnect system. Although the electrical interconnect system of the present invention is particularly suitable for use in connection with high-density systems, it may also be used with high-power systems or other systems.
B. DESCRIPTION OF THE RELATED ART
Electrical interconnect systems (including electronic interconnect systems) are used for interconnecting electrical and electronic systems and components. In general, electrical interconnect systems contain both a projection-type interconnect component, such as a conductive pin, and a receiving-type interconnect component, such as a conductive socket. In these types of electrical interconnect systems, electrical interconnection is accomplished by inserting the projection-type interconnect component into the receiving-type interconnect component. Such insertion brings the conductive portions of the projection-type and receiving-type interconnect components into contact with each other so that electrical signals may be transmitted through the interconnect components. In a typical interconnect system (e.g., the pin grid array of FIG. 29, discussed in detail below), a plurality of individual conductive pins 101 are positioned in a grid formation and a plurality of individual conductive sockets (not shown in FIG. 29) are arranged to receive the individual pins, with each pin and socket pair transmitting a different electrical signal.
High-density electrical interconnect systems are characterized by the inclusion of a large number of interconnect component contacts within a small area. By definition, high-density electrical interconnect systems take up less space and include shorter signal paths than lower-density interconnect systems. The short signal paths associated with high-density interconnect systems allow such systems to transmit electrical signals at higher speeds. In general, the higher the density of an electrical interconnect system, the better the system.
Various attempts have been made in the past at producing an electrical interconnect system having a suitably high density. One electrical interconnect system that has been proposed is shown in FIG. 1(a).
The electrical interconnect system of FIG. 1(a) is known as a post and box interconnect system. In the system of FIG. 1(a), the projection-type interconnect component is a conductive pin or post 101, and the receiving-type interconnect component is a box-shaped conductive socket 102. FIG. 1(b) is a top view of the interconnect system of FIG. 1(a) showing the post 101 received within the socket 102. As can be seen from FIG. 1(b), the inner walls of the socket 102 include sections 103 and 104 which protrude inwardly to allow a tight fit of the post 101 within the socket. FIGS. 1(a) and 1(b) are collectively referred to herein as "FIG. 1."
Another electrical interconnect system that has been proposed is illustrated in FIG. 2(a). The electrical interconnect system of FIG. 2(a) is known as a single beam interconnect system. In the system of FIG. 2(a), the projection-type interconnect component is a conductive pin or post 201, and the receiving-type interconnect component is a conductive, flexible beam 202. FIG. 2(b) is a top view of the interconnect system of FIG. 2(a) showing the post 201 positioned in contact with flexible beam 202. The flexible beam 202 is biased against the post 201 to maintain contact between the flexible beam and the post. FIGS. 2(a) and 2(b) are collectively referred to herein as "FIG. 2."
A third electrical interconnect system that has been proposed is shown in FIG. 3(a). The electrical interconnect system shown in FIG. 3(a) is known as an edge connector system. The projection-type interconnect component of the edge connector system includes an insulative printed wiring board 300 and conductive patterns 301 formed on the upper and/or lower surfaces of the printed wiring board. The receiving-type interconnect component of the edge connector system includes a set of upper and lower conductive fingers 302 between which the printed wiring board 300 may be inserted.
FIG. 3(b) is a side view of the system illustrated in FIG. 3(a) showing the printed wiring board 300 inserted between the upper and lower conductive fingers 302. When the printed wiring board 300 is inserted between the conductive fingers, each conductive pattern 301 contacts a corresponding conductive finger 302 so that signals may be transmitted between the conductive patterns and the conductive fingers. FIGS. 3(a) and 3(b) are collectively referred to herein as "FIG. 3."
A fourth electrical interconnect system that has been proposed is shown in FIG. 4. The electrical interconnect system shown in FIG. 4 is known as a pin and socket interconnect system. In the system of FIG. 4, the projection-type interconnect component is a conductive, stamped pin 401, and the receiving-type interconnect component is a conductive, slotted socket 402. The socket 402 is typically mounted within a through-hole formed in a printed wiring board. The pin 401 is oversized as compared to the space within the socket 402. The size differential between the pin 401 and the space within the socket 402 is intended to allow the pin to fit tightly within the socket.
The interconnect systems of FIGS. 1 through 4 are deficient for a variety of reasons. For example, the interconnect components in these systems generally include plating on each external and internal surface to ensure adequate electrical contact between the projection-type and receiving-type components. Since plating is typically accomplished using gold or other expensive metals, the systems of FIGS. 1 through 4 can be quite costly to manufacture.
Performance-wise, the edge connector system of FIG. 3 is subject to capacitance problems and electromagnetic interference. Likewise, the pin and socket system of FIG. 4 requires a high insertion force to insert the pin 401 within the slotted socket 402, and will not fit together properly in the absence of nearperfect tolerancing.
The main problem associated with the systems of FIGS. 1 and 2 (when arranged, for example, as in FIG. 29), the system of FIG. 3 (when arranged, for example, in a pair of rows), and the system of FIG. 4 (when arranged, for example, as in FIG. 3(a)) is that these systems are not high enough in density to meet the needs of existing and/or future semiconductor and computer technology. Interconnect system density has already failed to keep pace with semiconductor technology, and as computer and microprocessor speeds continue to climb, with space efficiency becoming increasingly important, electrical interconnect systems having even higher densities will be required. The electrical interconnect systems discussed above fall short of current and contemplated interconnect density requirements.